1. Field of the Invention
The present invention relates to a work crystal orientation adjusting method and apparatus, in which, before cutting a work formed of semiconductor material, magnetic material, ceramics or the like hav ing a crystal structure using a wire, the crystal orientation of the work is adjusted.
2. Description of the Prior Art
Generally, in a wire saw, there are disposed a plurality of working rollers at predetermined intervals and, along the respective outer peripheries of these working rollers, there are formed a plurality of annular grooves at a predetermined pitch. Also, between the respective working rollers, a piece of wire is wound sequentially around the annular grooves thereof. Further, a work support mechanism is disposed in correspondence to the wire arranged between the working rollers, while a work is removably mounted on the lower portion of the work support mechanism. And, while the wire is being made to travel, slurry containing float grains is supplied onto the traveling wire and, in this state, the work support mechanism brings the work into pressure contact with the wire to thereby execute a cutting operation or similar operations on the work. By the way, there is also known a wire. saw of a type in which the positions of the wire and work are reversed, that is, turned upside down, while the other remaining portions thereof are quite the same as the above-mentioned type wire saw in structure.
In this type of wire saw, it is necessary that the crystal orientation of the work is previously measured and, based on the measured result, the direction of the work must be adjusted in order for the crystal orientation thereof to be able to correspond to the traveling direction of the wire with a predetermined position relation. For this reason, in the conventional wire saw, the work support mechanism includes an orientation adjust mechanism which is used to adjust the direction of the crystal orientation in the rotational direction of the work and in the horizontal direction.
By the way, in the present patent specification, "to adjust the direction of the crystal orientation" is expressed simply as "to adjust the crystal orientation".
Referring back to the conventional wire saw, after the work is mounted on the work support mechanism, using the orientation adjust mechanism, the work is rotated around the center axis thereof to thereby adjust its crystal orientation in its rotational direction as well as the center axis of the work is shifted in a horizontal plane to thereby adjust the crystal orientation in the horizontal direction.
However, in this conventional adjusting method, the orientation adjust mechanism for adjusting the direction of the work crystal orientation in the rotational direction of the work and in the horizontal direction must be provided in the work support mechanism of the wire saw. This raises a problem that the wire saw is complicated in structure.
Also, in the above-mentioned conventional structure, since it is necessary to adjust the crystal orientation of the work in the rotational direction and in the horizontal direction after the work is mounted on the work support mechanism of the wire saw, the working time including the adjusting time of the work is long as a whole to thereby lowering the working efficiency.
Also, in the conventional wire saw, because the work support mechanism includes only one orientation adjust mechanism, it is impossible that a plurality of works having different crystal orientations are mounted and are cut at the same time while the crystal orientations are matched to one another. In other words, in the conventional wire saw, one work is mounted on one work support tool, the support tool with the work mounted thereon is mounted on the work support mechanism and the work crystal orientation is adjusted, and, after then, the work is cut; that is, whether the work is a short work or a long work, the work can be cut or worked simply one by one. Therefore, the working efficiency of the wire saw is poor and thus the productivity thereof is low.
Also, it can be contrived that a plurality of orientation adjust mechanisms are provided in the work support mechanism and a plurality of works having different crystal orientations are mounted on the work support mechanism and adjusted in their respective crystal orientations by their corresponding orientation adjust mechanisms and, after then, the work can be worked at the same time. However, in this case, the structure of the work support mechanism is extremely complicated and, in addition to this, each work must be adjusted in the crystal orientation in two directions before the cutting of it is started, which lowers the operation efficiency and prolongs the adjusting time, with the result that the productivity of the working operation is not so high.
On the other hand, there is also proposed a structure in which the orientation adjust mechanism is not provided in the work support mechanism but adjust mechanisms for adjusting the crystal orientation in two directions are provided in the work support tool before it is mounted on the work support mechanism. However, in this case as well, the work support tool is complicated in structure and, when a plurality of adjust mechanisms are provided in the work support tool are provided, then the work support tool is further complicated in structure.